Stoker fired forced draft boiler



Feb. 11, 1941. E. H. BAER STOKER FIRED FORCED DRAFT-BOILER Filed March 25, 1940 unmw Patented Feb. 11, 1941 UNITED STATES PATENT ore 5 Claims.

This invention relates to improvements in boilers of the type employed in connection with the production of hot water for use in hot water heating systems and for similar purposes.

5 It is the object of this invention to provide in an insulated jacketed boiler flue ways of great length with the chimney connection to the flues being located at the bottom of the boiler so that the intense heat generated within the boiler is forced and guided through the long flue ways and down along the water jackets so that the same will absorb practically all the heat from the gases before they escape through the chimney. The arrangement of the flue ways and water 15 jackets is such that the boiler will have a very large thermal efiiciency so that as indicated above practically all of the heat values of the fuel will be transferred to the water.

Another object of the invention is to provide 7 20 within the fire chamber of the boiler a stoker fired mechanism and to further provide in the chimney an automatic damper which will prevent the chimney draft from cooling the boiler.

With the foregoing and other objects in view, 25 the invention resides in the novel arrangement and combination of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed may 30 be made Within the scope of what is claimed without departing from the spirit of the invention.

A practical embodiment of the invention is illustrated in the accompanying drawing, wherein: V Figure 1 is a vertical sectional view through 35 boiler showing details of construction.

Figure 2 is a partial elevational view taken on line 22, Figure 1, showing boiler flame tubes or flues.

Referring to the drawing I0 denotes the boiler 116 which is preferably of round construction to provide a round fire box II, the boiler being fabricated in any desired manner so as to provide a maximum of water jacketed surfaces l2, l3, l4, I5, 16 and IT, in the manner well known. Housed in 45 the fire chamber H at the base of the boiler is a forced draft coal stoker retort I8 of the character well known. The space between said water jacketed surfaces and the outer wall of the boiler constitutes the boiler water jacket I9.

50 Also forming part of the aforesaid mentioned water jacketed surfaces are the front and rear vertical supporting plates 20 and 2| to which are suitably secured the ends of a plurality of horizontal boiler flame tubes 22. The front support- 55 ing plate 20 is spaced inwardly from the front inner jacket surfaces l3 and I4 to provide a primary flue chamber 23. Provided in the front wall of the boiler H1 is an upper flue clean-out door 24 and similarly beneath the same there isprovided a fire-inspection door 25 for the fire chamber 5 Preferably the attachment of the flame tubes 22 to the front supporting plate 20 is such as to be located thereon directly opposite to the clean-out door 24 so as to permit ready access to each of said tubes for cleaning or repair, in the manner readily apparent.

Parallel to the rear supporting wall 2| and the rear boiler wall and in spaced relation thereto is a vertical jacket wall 26 arched at its upper end as at 21 and connected to the rear supporting wall 2|. The lower ends of both walls 2| and 26 are connected to the lower end of jacket wall I 1 while the vertical sides of said walls 2| and 26 are suitably connected to opposed sides of the circular wall IS. The space defined between the walls 2| and 26 constitutes a vertical chimney flue chamber 28, the upper portion of which is in communication with the primary flue chamber 23 by means of the boiler flame tubes 22. Thus, said flame tubes 22 constitute an intermediate flue 25 chamber while the chimney flue 28 constitutes a final flue chamber.

It will be noted that the water jacket l9 considered in its entirety in part overhangs the fire chamber H, and in part includes a rear portion 30 housing the final or chimney flue 28. Afiixed to the lower or exit end of the chimney flue 28 is one end of a pipe 30 which extends outwardly of the boiler l0 and has connected to its other end a pipe 3| which in turn connects with the chimney of the house or building (not shown).

Preferably the terminal end of the pipe 30 is provided with a fly-ash clean-out door 32, and in the chimney pipe 3| there is provided a conventional automatic damper 33 which functions to prevent the chimney draft from cooling the boiler. Should the chimney draft be greater than the forced draft of the stoker the automatic damper will draw air from the heater room.

Suitably attached to the upper wall of the boiler I0 is a hot water outlet pipe 35 conducting the hot water to the radiators, while the return pipe 36 is connected to the lowermost portion of the water jacket preferably at the boiler rear wall as shown.

A hot water motor driven circulator 31 may be 5 provided in the return pipe 36 if desired. Interconnected between the outlet and return pipes 35 and 36 is an auxiliary heater 38 for domestic hot water containing a coil 39 connected at its upper end by pipe 40 to the domestic hot water tank (not shown) and at its lower end to the return pipe 4| from said domestic hot water tank. The auxiliary heater 38 is connected by pipe 42 to the outlet hot water pipe 35 and by pipe 43 to the inlet hot water pipe 36. Provided in the pipe 43 is a thermocheck 44.

Suitably located in the water jacket wall is a safety plug 45 constructed of a soft material of low melting point and will release the Water in the water jacket should the stoker fail to shut ofi and the boiler become overheated. The boiler may also be provided with a thermostat 46.

Surrounding the boiler is a boiler jacket 41 preferably of square foundation. Filling the space 48 between the jacket 41 and outer boiler wall is a heavy insulation (not shown) of any desired character applied directly to the boiler.

From the above it will be appreciated that an extremely eflicient heating system is provided. The heat generated by the retort l8 within the fire chamber ll passes upwardly first through the primary flue chamber 23, then through the boiler flame tubes 22 or intermediate flue chamber and then down through the chimney or final flue 28 out intothe chimney pipes 30 and 3|. The large heating surface thus provided along with the normal water jacket surfaces will act to take up practically all of the heat in the gases so that the gases escaping up the chimney are relatively cool, thus effecting a high economy in the operation of the furnace as well as obtaining a maximum of efiiciency.

Having thus described the invention, what is claimed is: I

l. A boiler comprising a fire chamber, a Vertical primary flue extending upwardly from said fire chamber at the front of said boiler, a horizontal intermediate fiue comprising a plurality of flame tubes, and a final chimney flue extend- 4( ing vertically downwardly at the rear of said boiler, said flame tubes communicating the up per portions of said primary flue and final chimne'y flue, and a chimney pipe communicating the lowermost portion of said final chimney flue 45 with the atmosphere, said boiler being so constructed as to provide a water jacket formed to surround said primary, intermediate and final chimney flues.

2. A boiler comprising a fire chamber and a built-in water jacket encircling said fire chamber, a vertical primary flue in said water jacket extending upwardly from said fire chamber at the front of said boiler, a final chimney flue in said water jacket extending vertically downwardly at the rear of said boiler, and a horizontal intermediate flue extending through said water jacket and communicating the upper portions of both said primary flue and final chimney flue, whereby the heated gases of combustion generated in said fire chamber will pass sequentially through said primary, intermediate and final chimney flues, and chimney pipe means connected to the lowermost portion of said final chimney flue for conducting said gases away from said boiler.

3. A boiler comprising a fire chamber and a built-in water jacket encircling said fire chamber, a vertical primary flue in said water jacket extending upwardly from said fire chamber at the front of said boiler, a final chimney flue in said water jacket extending vertically downwardly at the rear of said boiler, and a horizontal intermediate flue comprising a plurality of horizontal flame tubes extending through said water jacket and communicating the upper portions of both said primary flue and final chimney flue, whereby the heated gases of combustion generated in said fire chamber will pass sequentially through said primary, intermediate and final chimney flues, and chimney pipe means connected to the lowermost portion of said final chimney flue for conducting said gases away from said boiler.

said water jacket and communicating the upper portions of both said primary flue and final chimney flue, that portion of said water jacket housing said intermediate flue being vertically spaced above said retort and comprising the main upper wall of said fire chamber, the arrangement of said flues being such that the heated gases of combustion generated in said fire chamber will pass sequentially through said primary, intermediate and final chimney flues, and chimney pipe means connected to the lowermost portion of said final chimney flue for conducting said gases away from said boiler.

5. A circular boiler comprising a circular fire chamber housing a forced draft stoker retort and a built-in water jacket encircling said fire chamber, a vertical primary flue in said water jacket extending upwardly from said fire chamber at the front of said boiler, a final chimney flue in said water jacket extending vertically downwardly at the rear of said boiler, and a horizontal intermediate flue comprising a plurality of horizontal flame tubes extending through said water jacket and communicating the upper portions of both said primary flue and final chimney flue, that portion of said water jacket housing said intermediate flue being vertically spaced above said retort and comprising the main upper wall of said fire chamber, the arrangement of said flues being such that the heated gases of combustion generated in said fire chamber will pass sequentially through said primary, intermediate and final chimney flues, and chimney pipe means connected to the lowermost portion of said final chimney flue for conducting said gases away from said boiler.

EARLE HENRY BAER. 

